The invention relates to sea water pumps for marine propulsion systems.
Sea water pumps for marine propulsion systems are known in the prior art, for example Mercury Marine Sea Water Pump Serial No. C849992 thru D725646 and D725647 thru F213244, 465 Engine, pages 40-43, January 1995, and U.S. Pat. Nos. 4,940,402, 4,392,779, 4,718,837 and 2,466,440, incorporated herein by reference. A generally cylindrical pumping chamber is defined by a generally cylindrical sidewall extending axially between opposite endwalls. A multi-vaned rotary impeller in the chamber is driven by an axially extending impeller drive-shaft. The impeller has a plurality of flexible vanes extending radially outwardly therefrom in the chamber and having outer tips engaging the sidewall. During rotation of the impeller shaft, the vanes move through portions of varying flexure to draw water in through an inlet port and discharge same through a discharge port. The endwalls of the chamber are engaged by the axial ends of the vanes in sealing, sliding relation.
In one aspect of the present invention, increased pumping capacity is enabled by enhanced intake and discharge port structure providing additional water flow.
In another aspect of the invention, both improved reliability and lower manufacturing cost are afforded by simplified housing structure providing multiple functions with a reduced number of parts.
In another aspect of the invention, previous areas of potential leakage are eliminated.